Surgical needle and apparatus for grinding the same

Abstract: A surgical needle (1) for sutural treatment having a body (2) triangle or polygon in cross section includes a blunt needle point (P) with a plate or round end and at least two cutting edges (5B,5C) to prevent a health provider from hurting herself or himself by mistake even if the needle (1) contacts the tissues of the health provider and to provide a property that once the needle (1) enters the tissues the needle (1) passes through the tissues smoothly. A first face (4A) of the body (2) could be ground by a grinding apparatus (20) specially made for the surgical needle (1) to form a tapered slope and the cutting edges (5B,5C). Pressing a material piece of the needle in a V-shaped groove (11) forms second and third faces (4B,4C) and readily produces a high quality surgical needle (1).

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a surgical needle for a suture and, more particularly, to a surgical needle having a triangular cross section at its body and a grinding apparatus for manufacturing the surgical needle. 2. Description of Related Art As conventional surgical needles, known are needles such as disclosed in Japanese Utility Model Publication, No. Showa-62-23,457 and Japanese Patent Publication, No. Heisei-1-54,075. JP-1195892 discloses a curved suture needle provided with two longitudinal cutting edges. The needle disclosed has a sharp point. Any of these surgical needles has a triangular cross section and a pointed body to reduce resistance against penetration when passed through the tissues. Problems of infections among health providers and patients involved in infectious diseases, such as hepatitis, AIDS, MRSA (Methicillin-Resistant Staphylococcus Aureus), and whatever, are raised as major social problems these days. Such infections may happen by way of a fluid, such as blood or the like, as a carrier when a health provider, such as a doctor or the like, hurts herself or himself by mistake with the medical instrument. Hence, a needle with a sharp point may hurt a health provider by herself or himself, and the health provider must pay close attention to handle the needle since in such situations the health provider has to take tremendous risks of infection between them, so that the health provider has to endure enormous mental pressure caused by such risks. SUMMARY OF THE INVENTION It is an object of the invention to provide a safe surgical needle hardly to hurt a health provider even if the provider handles it in a wrong manner and thereby to solve the problems happening in association with medical circumstances these days. The foregoing object is accomplished with a surgical needle having a triangular cross section at a body and including a face tapered along a longitudinal direction of the body, a pair of cutting edges provided at opposite ends of the face in a transverse direction of the body. An edge provided in opposition to the face is blunted so that the needle point never enters into tissues unless a predetermined force or above is applied thereto, thereby blunting a needle point to prevent a health provider from being hurt by mistake. After pushed into tissues by a certain force, the surgical needle passes through the tissues with the cutting edges incising the tissues under reduced resistance against penetration of the needle. According to a preferred embodiment of the invention, the cutting edges are formed separately from the needle point. The tapered face could be ground in a transverse direction perpendicular to the longitudinal direction to make the cutting edges sharper. In another aspect of the invention, the body of a surgical needle has a polygonal cross section. The surgical needle includes a first face tapered along a longitudinal direction of the body so that the body has thinner thickness on a tip side thereof, a pair of cutting edges provided at opposite ends of the first face in a transverse direction of the body, and a second face provided in opposition to the first face. The needle point of the surgical needle is formed in a plate shape so as to be blunt by the first and second faces. The blunt needle point gives increased resistance when pushed onto tissues, thereby reducing the risks of hurting health providers by mistake. In addition, an apparatus for grinding a face of a surgical needle tapered along a longitudinal direction of a body of the surgical needle is able to manufacture the surgical needle having a polygonal cross section at the body. The apparatus includes a grinder for grinding in a transverse direction perpendicular to the longitudinal direction, and a workpiece table for holding a plurality of the surgical needles. The workpiece table includes a top face defining a shape of a ground face of the surgical needle, and a plurality of grooves for holding a bottom side of each of the surgical needles, formed on the top face. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and features of the invention are apparent to those skilled in the art from the following preferred embodiments thereof when considered in conjunction with the accompanied drawings, in which: Fig. 1 is a perspective view showing a surgical needle according to a preferred embodiment of the invention; Fig. 2 is a perspective view showing a cutout of the body of the surgical needle in Fig. 1; Figs. 3(a) to 3(c) are fragmentary illustrations showing a manufacturing process of a surgical needle in Fig. 1; Figs. 4(a), 4(b) are fragmentary illustrations showing operation of a grinding apparatus for grinding the surgical needle in Fig. 1; Figs. 5(a) to 5(f) are perspective views showing point shapes of surgical needles according to other embodiments of the invention; and Figs. 6(a) to 6(c) are cross-sectional diagrams illustrating molds used for pressing the surgical needles according to the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings in detail, in particular, to Figs. 1, 2, a surgical needle designated by numeral 1 according to a preferred embodiment of the invention is shown. As shown in Fig. 1, the surgical needle 1 is a curved needle for sutural treatments having a triangular cross section. A body 2 is arranged on a tip side of the surgical needle 1, and an eye 3 is located on a shaft side for holding a suture. The body 2 has three faces 4A, 4B, and 4C, and three edges 5A, 5B, and 5C at which the three faces meet. Among three faces, a first face 4A is an outer face of the curvature of the surgical needle 1, and is ground in a transverse direction by a polishing disk or the like. The other second and third faces 4B, 4C are made by press within a mold therefor. A first edge 5A, among three edges, is situated inside of the curvature of the surgical needle and has a blunt verge. Second and third edges located on opposite sides of the first face 4A have sharp verges. The body 2 has a configuration having a cross section as shown in Fig. 2 in succession up to a needle point P of the body. The first edge 5A has a dull, flattened ridge and reaches the needle point P with keeping such a flattened top. To the contrary, the first face 4A is a successive surface that approaches to the first edge 5A as getting close to the needle point P, and makes the needle point P to be in a shape like a spatula. On the other hand, although the second and third edges 5B, 5C are in succession up to the needle point P of the body 2, these edges 5B, 5C never meet at the needle point P to make the needle point to be blunt. That is, when the surgical needle 1 is put up onto tissues, such as skins, the needle point P of the body 2 always contacts to the tissues through a liner or areal section, so that the surgical needle penetrates the surface of the tissues only when applied with a predetermined force or above. Once the needle 1 enters the tissues, sharp cutting edges 5B, 5C incise the tissues to reduce resistance against penetration, thereby allowing the health providers to handle the surgical needle 1 smoothly. Referring to Figs. 3, 4, a manufacturing process of the body 2 will be described. The curved needle as described in this embodiment is furnished to this shape by bending after the needle body is formed from a straight shaped material piece. First, a material piece 1a made of stainless steel or the like is fixed to a mold 10 having a V-shaped groove 11 and pressed from the top side, as shown in Fig. 3(a). The material piece 1a, initially in a cylindrical shape, is transformed into a triangular prism by means of the V-shaped groove 11 through this work. The V-shaped groove is composed of a bottom face 11a and the groove side walls 11b, 11c by which the second and third faces 4B, 4C, pressed faces of the needle, are made. The bottom face 11a of the V-shaped groove 11 crushes the first edge 1A formed between the second and third faces 4B, 4C to be blunted. When pressed from its top side, the material piece 1a provides protruded portions, or burrs 7, 7, protruded from pressed surface at top opposite ends in the case that the inserted material 1a has a large volume. As shown in Fig. 3(b), a ground face 4A is formed at a portion opposite to the first edge 5A by grinding. This grinding work is conducted with a grinding apparatus shown in Fig. 4. The grinding apparatus 20 includes a grinding disk 21 whose a rotary side face is used as a grinding face 21a, and a workpiece table 22 for setting a plurality of material pieces 1a through clamping. The grinding face 21a of the grind disk 21 contours a side face in the form of a part of an ellipse as shown in Fig. 3(b). In Fig. 4(b), a perspective view of the workpiece table 22, a plurality of the V-shaped grooves 23 juxtaposed to one another are drilled on the top face 22b of the workpiece table body 22a. The triangular prism material pieces 1a machined at the process shown in Fig. 3(a) are set into the grooves 23. These material pieces 1a are fixed by being suspended between the fixing plate 22 and the workpiece table body 22a. The top face 22b of the workpiece table body 22a has a gentle slope so as to coincide with the grinding side face 21b of the grind disk 21. Therefore, even where the grind disk 21 works for grinding, the grinding face 21a never interferes with the top face 22a of the workpiece table 22. In addition, since the material piece 1a is held by the V-shaped groove at the bottom side thereof, the material piece 1a is free from stress during grinding work, so that a high-quality surgical needle is produced. The grinding face 21a of the rotating grind disk 21 contacts with the tip of the material piece 1a in such a manner, thereby forming the first face 4A on the material piece 1a as a ground face. Fig. 3(b) depicts a situation during grinding work. The ground face having a gently curved side shape is formed on and on across the material 1a, and, as this grinding work goes on, the burrs 7, 7 are ground away, thereby forming sharp edges. This grind work is done by the grind disk 21 moving back and forth by a number of times. Consequently, the grind disk 21 always grinds in the transverse direction perpendicular to the longitudinal direction of the material piece 1a, so that the first face 4A becomes a ground face with edges transversely oriented, thereby forming edges having excellent cutting property. When the grind work ends, there produces the material piece 1a having the body 2 as shown in Fig. 3(c). That is, the first edge 5A having the flatten ridge and the ground first face 4A come close with one another at the needle point P of the body 2 to form a plate shape. The adjustment of the down feed amount of the grind disk allows thickness of the end of the needle point P to be set in various ways and, as a matter of course, allows the end of the needle point P to be formed into a liner shape. The second and third edges 5B, 5C are formed on the opposite sides, of the first face 4A, at which shaped edges are formed. On the other hand, such transverse grinding does not work against the edge at the needle point P because it is done in the extending direction of the edge, thereby producing the needle point P not easy to incise. After this process, the material piece 1a is made to a surgical needle 1 as shown in Fig. 1 through a drilling process of an eye 3 not shown and a bending process. The surgical needle 1 according to this embodiment easily obtains configuration feature described above as only by being pressed and ground, thereby providing high productivity. It is to be noted that although in the manufacturing process of the surgical needle according to the invention the material piece 1a is transformed to the triangular prism by press in Fig. 3(a), the material piece could be pressed into a triangular pyramid using another mold after ground in a cone and then be furnished to a body having a suitable triangular cross section during a grinding process done afterward. Although the surgical needle 1 is constituted so that the first face 5A is arranged inside of the curvature, the first face could be arranged outside of the curvature. Moreover, although the surgical needle 1 has the eye 3, as a construction for threading a suture, opened at a side face of the shaft of the needle, the surgical needle could be an eyeless needle with a long hole drilled to be open in the longitudinal direction of the body from the end of the shaft. In addition, although the needle has the curvature in this embodiment, the needle could be straight or hook shaped. Referring to Figs. 5, 6, other shapes of the surgical needle according to the invention are shown. Fig. 5 shows perspective views of various body types of the needle according to the invention. Fig. 6 shows vertical cross-sections of various types of molds used for pressing. In Fig. 5(a), the body 2 has a knife shaped, ellipse, and round point. The top of the first edge 5A is crushed to be flatten, so that the point is in a plate shape as result of grinding. A body 2B shown in Fig. 5(b) has a sharper ridge of the first edge 5A, and according to the sharper ridge the point P becomes sharper. A body 2C shown in Fig. 5(c) is sharpened more than the body 2 or 2B by grinding. In this body 2C, second and third edges 5B, 5C are formed separately from the needle point P, so that the point P is round and blunt. A body 2D, as shown in Fig. 5(d), the second and third faces 4B, 4C are concave and respectively have an indentation along the longitudinal direction. A body 2E, as shown in Fig. 2E, has a rectangular cross section, as different from the bodies 2, 2B, to 2D having triangular cross sections. This body 2E has the four edges 15A to 15D, but it is enough that the third and forth edges 15C, 15D have sharp ridges. The first face 14A and the second face 14B in opposition to the first face approach to each other as they come close to the point P, and the point P becomes a plate shape. It is to be noted that although the body 2E has an areal end at the point P, the end could be a liner shape of a body 2F as indicated in Fig. 5(f) by adjustment of grinding amount. Such various types bodies 2, 2B to 2F are readily formed by changing molds used for press. Figs. 6(a) to 6(c) show examples of mold shapes. The body 2B shown in Fig. 5(b) can be formed with a mold in Fig. 6(a). This mold has no bottom face in the V-shaped groove 31 as different from the mold of the embodiment described above and shown in Fig. 2(a), and therefore, a material piece 1a pressed by this mold has a sharper first edge 5A. However, though the V-shaped groove 31 has a tapered lower end, the tapered end is not transferred to the material 1a because of the nature of press, and the first edge 5A remains to be blunt. Adjustment of capacity of the mold can prevent the material piece 1a from being pressed with burrs at the partition line of the mold as shown in Fig. 6(a). The body 2D in Fig. 5(d) is pressed by a mold 41 shown in Fig. 6(b). Using such a mold 41 allows the concave second and third faces 5B, 5C to be readily formed. The bodies 2E, 2F in Figs. 5(e), 5(f) can be produced using a groove 51 having a rectangular cross section as shown in Fig. 6(c). Resistance against entering of the surgical needle 1 into tissues is determined by a contact area with the tissues at a time that the point P is put up on the tissues. Changing the shape of the point to various ones allows the resistance to be adjusted. That is, it is enough that the point P has at least a shape by which pressure on the needle is dispersed, and since the skin is elastic, the end of the body might be a liner or areal shape as far as an incising point of the skin does not occur. Thus, diversifying press formation of the material piece 1a using various types molds allows various needle points to be produced without changing other processes, for example, grinding process. Accordingly, to use this manufacturing process enables to readily produce a safe point of the surgical needle according to this invention with various shapes in association with purpose in use of the surgical needle. It is understood that although the present invention has been described in detail with respect to preferred embodiments thereof, various other embodiments and variations are possible to those skilled in the art which fall within the scope of the invention, as defined by the following claims.

Claims: A surgical needle (1) having a polygonal cross section at a body (2 or 2E) thereof, said surgical needle comprising: a first face (4A or 14A) tapered along a longitudinal direction of said body (2 or 2E) so that said body (2 or 2E) is of thinner thickness on a tip side thereof than on the opposite side; and a pair of cutting edges (5B,5C or 15C,15D) provided at opposite sides of said first face (4A) or (14A) in a longitudinal direction of said body (2 or 2E); and wherein either: a) a blunt edge (5A) is provided in opposition to said face (4A), said blunt edge (5A) expanding to a needle point (P) so that said surgical needle (1) has no sharp point; or b) a second face (14B) is provided in opposition to said first face (14A) and a needle point (P) formed in a plate shape by and between said first and second faces (14A, 14B), with the proviso that when the needle shape is described by option a) then the cross-section of the body (2) is triangular. A surgical needle (1) as claimed in Claim 1, wherein at said needle point (P) said cutting edges (5B, 5C or 15B, 15C) are spaced apart. A surgical needle (1) as claimed in Claim 1, wherein said cutting edges (5B, 5C or 15B, 15C) meet at a point. A surgical needle (1) as claimed in any one of Claims 1 to 3, wherein said first face (4A or 14A) is ground in a transverse direction perpendicular to said longitudinal direction. A surgical needle (1) as claimed in any one of Claims 1 to 4, wherein said body (2 or 2E) has curvature. A surgical needle (1) as claimed in any one of Claims 1 to 4, wherein said body (2 or 2E) is straight. A surgical needle (1) as claimed in any one of Claims 1 to 6, wherein said first face (4A or 14A) is formed by grinding and other faces (4B, 4C or 14B) of the surgical needle (1) are formed by press. A surgical needle as claimed in any one of Claims 1 to 7, wherein said needle (1) has a triangular cross section. An apparatus (20) for grinding a face of a surgical needle (1a) tapered along a longitudinal direction of a body (2) of the surgical needle (1a) said surgical needle having a polygonal cross section at said body (2), said apparatus (20) comprising: a grinder for grinding in a transverse direction perpendicular to said longitudinal direction; and a workpiece table (22) for holding a plurality of said surgical needles (1a), said workpiece table (22) comprising: a top face (22b) defining a shape of a ground face of said surgical needle (1a); and a plurality of grooves (23) for holding a bottom side of each of said surgical needles (1a), formed on said top face (22b). An apparatus as claimed in Claim 9, wherein said groove (23) has a V-shaped cross section. An apparatus (20) as claimed in Claim 9, wherein said groove (23) has a flat bottom and inclined side walls. An apparatus (20) as claimed in any one of Claims 9 to 11, wherein said grinder is a grind disk (21). An apparatus as claimed in Claim 12, wherein said grind disk (21) has a grinding side face (21a) in a shape coinciding with the shape of the top face (22b).

Inventors: MATSUTANI KANJI, SAITOH AKIRA, YAGISAWA HIROSHI, MATSUTANI, KANJI, SAITOH, AKIRA, YAGISAWA, HIROSHI
Applicants: MATSUTANI SEISAKUSHO, KABUSHIKI KAISHA MATSUTANI SEISAKUSHO
Application year: 1994
Main classification: A61B17
IPC codes: A61B17, A61F2, B24B19, D05B85, B21G1